The present invention relates generally to digital graphic display processors and particularly to programmable integrated hardware area fill, conics and vector generators forming a working part of a graphics generator that is used as a component of the graphic display processor.
Real time digital electronic displays are used in many applications such as miliary command and control workstations and air-traffic control systems. In these displays, the displayed information typically comprises real-time processed data generated by a host processor adapted to receive the basic real-time information from one or more radars, communications systems and/or other data processors. These data are then combined with one or more graphic primitives, such as a circle, ellipse or polygon, along with generated alphanumerics, mask areas and texture patterns to provide a relatively easily understood comprehensive graphic display on an output device such as cathode-ray tube. In contemporary systems, the various components of the graphics display such as the graphic primitives, mask windows, fill texturing and the like are provided either by a general purpose computer based graphics generator or by a hardware specific graphics generator. Of these, general purpose graphics generators offer system versatility but usually must sacrifice some degree of system performance for ease of programming. On the other hand, hardware specific graphics generators, called cogenerators, provide good system performance.
Increasing demands on military command and control systems, military and civil air-traffic control systems and the like have created a need for high performance graphics cogenerators which, in addition, provide a versatile and easily implemented programming capability. A key element in such a cogenerator is a processor capable of generating a multiplicity of filled areas, and circular, elliptical and polygonic shapes. These shapes may be directly placed onto the display screen and color and texture information may be applied within the areas and shapes to form the final output display. In contemporary graphics cogenerators, area fill generators are typically slow, or are simple, single channel devices which require repetitive retrieval of information from a remote memory and which are therefore capable of providing only a limited range of output display forms in the time allotted for such provision during system cycling. It is therefore desirable to provide a programmable integrated hardware graphics generator which is capable of producing a wide variety of filled areas, and circular, elliptical and polygonic output forms without slowing the overall speed of system operation.